Embodiments of the invention generally relate to systems and methods for processing solid powders. More particularly, embodiments of the invention relate to systems and methods for conveyance and gasification of solid powders such as solid carbonaceous fuel powders.
Gasification is a process that enables the conversion of carbonaceous fuels, such as coal into a combustible gas, such as coal gas or synthesis gas. Generally, gasification processes include conveying carbonaceous fuels into gasifiers along with a controlled and/or limited amount of oxygen and other steams. A stable and controllable flow of such carbonaceous fuels into gasifiers is beneficial for obtaining desirable gasification performance.
In conventional gasification systems, pneumatic conveyance technologies are usually employed to convey carbonaceous fuels into gasifiers. Such gasification systems comprise storage tanks, gasifiers and a plurality of pipelines in fluid communication with respective tanks and gasifiers. The storage tanks receive carbonaceous fuels and carrier gases through the pipelines. With the introduction of the carrier gases into the storage tanks, the pressures of the storage tanks increase to desired levels, which are higher than pressures in the gasifiers so as to generate pressure differences between such storage tanks and gasifiers. A solid-gas mixture then may be conveyed from the storage tanks into the gasifiers.
However, in such conventional gasification systems, the flow of the carbonaceous fuels into the storage tanks may be not uniform. As a result, the conveyance of the carbonaceous fuels into the gasifier may thus become unstable. This may generate temperature fluctuations in the gasifiers, which fluctuations are disadvantageous to the performance and service life of the gasifiers. Further, when such conventional gasification systems convey the carbonaceous fuels such as coal having higher moisture content, the carbonaceous fuels need to be dried to have a relative lower moisture level to avoid blockage of the conveyance into the gasifiers through the storage tanks. This drying process consumes more energy and increases the overall cost for the gasification process.
Therefore, there is a need for new and improved systems and methods for conveyance and gasification of solid powders.